Islamabad: The US embassy in Islamabad had said last year that the fight against al Qaeda and other militants operating in Pakistan will last 10-15 years, secret diplomatic cables released by WikiLeaks have revealed.

"As we work to prevent Pakistan-based attacks on the US and its forces, we should be clear that al Qaeda now wants more than just a safe haven in Pakistan," then US envoy to Pakistan Anne Patterson said.

"Defeating a growing witches` brew of al Qaeda, Taliban, local extremists and criminals will be a long 10-15 year fight," she wrote in a cable sent to Washington in February last year.

According to the DawnNews, the cable quoted Patterson as telling Washington of the mutual mistrust that has bedevilled US-Pakistan relations.

Ahead of Pakistan Foreign Minister Shah Mehmood Qureshi`s visit to the US in 2009 for a strategic dialogue, Patterson quoted Vice President Joe Biden as saying the relationship for too long has been transactional in nature.

"It also has been based on mutual mistrust," the envoy wrote, adding, "Pakistan hedges its bets on cooperation because it fears the US will again desert Islamabad after we get Osama bin Laden; Washington sees this hesitancy as duplicity that requires we take unilateral action to protect US interests."

She also said that although former president Pervez Musharraf made, after 9/11, a strategic shift to abandon the Taliban and support the US in the war on terror, neither side believed the other had lived up to expectations flowing from that decision.

"The relationship is one of co-dependency we grudgingly admit - Pakistan knows the US cannot afford to walk away," Patterson said, adding "the US knows Pakistan cannot survive without our support."